Using a stepdown transformer on a turbine

Discussion in 'General Electronics Chat' started by fabieville, May 1, 2011.

May 25, 2009
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I have a windblue 540 low wind turbine. It does not produce a lot of amps. The most I see out of it is about 1-4 amps but when it is spinning the voltage at open circuit goes up to all 30V easily. It is a 3 phase wind turbine.
This is my theory:
Run the 3 phase through a stepdown transformer. And when it produce voltage like 30VAC for eg. the transformer step it down to about 14VAC while increasing the current at the output so you have a lower voltage but a higher current going to the battery. With this method i would have a higher current going to my battery at all times.
Would my theory work?

2. marshallf3 Well-Known Member

Jul 26, 2010
2,358
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I'd verify that the 30V is still that when you put a load on it, if it is then a step down transformer could be used but finding something that steps 30V to 14V is going to be hard.

3. t_n_k AAC Fanatic!

Mar 6, 2009
5,448
783
You could try a 240V:110V transformer - which is pretty standard in some parts of the world.

Dec 26, 2010
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You would need to check that the frequency range of the output when running at different speeds was compatible with the transformer, which would typically be designed for 50Hz or 60Hz at its rated voltage, if designed for mains use. To avoid saturation, the voltage needs to be de-rated proportionally for lower frequencies.

Perhaps it would be better to rectify the generator output and use a switch-mode converter to feed the battery. This could provide a variable ratio, instead of the fixed one provided by the transformer.

5. marshallf3 Well-Known Member

Jul 26, 2010
2,358
201
Perhaps it would be better to rectify the generator output and use a switch-mode converter to feed the battery. This could provide a variable ratio, instead of the fixed one provided by the transformer.

This is far more common, using a buck/boost circuit somewhat compensates for variations in wind sped resulting in output voltage variations. On top of that if this is a three phase output the chances of finding such a transformer is next to nil, you'd have to have the knowledge to design and construct one yourself.

Rectifying a three phase source into DC is easy, it just takes 6 rectifiers.